You'd think measuring an engine's displacement would be simple, but there's a long history of trying to figure out how to ...

Rotary engines (also known as Wankel engines and Wankel rotary engines) are quite different from piston or "reciprocating" engines. One of the distinguishing features is that they don't need valves to ...

In a world dominated by pistons, the rotary engine was something different for motorists. It was the vision of German engineer Felix Wankel, built on the belief that the up-and-down motion of pistons ...

For a time, the Wankel rotary engine seemed like the future. In 1963, German automaker NSU—later absorbed into Audi—debuted the Wankel Spider, the first internal-combustion production car not powered ...